Underestimating body size may lead to better mental health, life satisfaction among overweight teens

While the underestimation of body size in adolescents with obesity/overweight has become more common, it has also led to less dieting, higher life satisfaction, and better mental health in both boys and girls, a recent study has found.

The study included overweight (body mass index ≥25 kg/m²) adolescents (aged 13–19 years) who had participated in The Young-HUNT1 (1995–1997; n=1,338) or The Young-HUNT3 (2006–2008; n=1,833) surveys. Self-report questionnaires and clinical examinations were accessed for the present study. Underestimation was defined as being overweight but perceiving oneself as being underweight or of average weight.

The proportion of participants who were overweight increased over time, jumping from 15.9 percent in the Young-HUNT1 survey to 24.1 percent in the Young-HUNT3 survey. At the same time, anxiety and depression increased in both boys and girls (p<0.001), though life dissatisfaction grew worse only in girls (p<0.001).

The proportion of participants who underestimated their body size likewise increased over time, from 31.2 percent to 44.2 percent in boys (p<0.001) and 17.1 percent to 30.9 percent in girls (p<0.001).

Multivariable logistic regression analysis showed that at both surveys, dieting behaviours were significantly but inversely associated with underestimation of body size.

During the second survey, both boys (odds ratio [OR], 0.39, 95 percent confidence interval [CI], 0.25–0.60) and girls (OR, 0.45, 95 percent CI, 0.16–0.66) who underestimated their body size were significantly less likely to have symptoms of depression and anxiety, as compared with counterparts who showed no such underestimation.

Similarly, both surveys revealed that those who underestimated their body size were around 50-percent more likely to report greater levels of life satisfaction.